Nitric Oxide Negatively Modulates Wound Signaling in Tomato Plants

Autor: Clarence A. Ryan, Martha L. Orozco-Cárdenas
Rok vydání: 2002
Předmět:
Zdroj: Plant Physiology. 130:487-493
ISSN: 1532-2548
0032-0889
Popis: Synthesis of proteinase inhibitor I protein in response to wounding in leaves of excised tomato (Lycopersicon esculentum) plants was inhibited by NO donors sodium nitroprusside andS-nitroso-N-acetyl-penicillamine. The inhibition was reversed by supplying the plants with the NO scavenger 2-(4-carboxiphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. NO also blocked the hydrogen peroxide (H2O2) production and proteinase inhibitor synthesis that was induced by systemin, oligouronides, and jasmonic acid (JA). However, H2O2 generated by glucose oxidase and glucose was not blocked by NO, nor was H2O2-induced proteinase inhibitor synthesis. Although the expression of proteinase inhibitor genes in response to JA was inhibited by NO, the expression of wound signaling-associated genes was not. The inhibition of wound-inducible H2O2 generation and proteinase inhibitor gene expression by NO was not due to an increase in salicylic acid, which is known to inhibit the octadecanoid pathway. Instead, NO appears to be interacting directly with the signaling pathway downstream from JA synthesis, upstream of H2O2synthesis. The results suggest that NO may have a role in down-regulating the expression of wound-inducible defense genes during pathogenesis.
Databáze: OpenAIRE